"Verily the lust of comfort murders the passion of the soul, and then walks grinning in the funeral."
-Kahlil Gibran, On Houses
Beware of your comfort zone. Great things happen when we challenge ourselves, both physically and mentally. You don't get fit without hard work. You don't learn new things without study. You don't build character without trials. Very few look back upon their life and see times of comfort and stability as their moments of greatest achievement.
If you value comfort too highly, you may be walking your passions and achievements straight to the grave.